RavenDB vs MongoDB: Which is Better? This White Paper compares the two leading NoSQL Document Databases on 9 features to find out which is the best solution for your next project.

Apache Phoenix is a SQL layer on top of HBase. Writing tracing information to tracing table "SYSTEM.TRACING_STATS" is optional and can be manipulated through the query statements "trace on" and "trace off."

can be replaced by any other query statements as preferred by the user to be executed between "trace on" and "trace off". All these queries belong to a single trace identified by a unique trace_id. But these queires may fork into multiple spans.